The Physical Basis of Society

acres Africa alloy America appears areas Asia atoms average bacteria birds black bass body carbon carbon dioxide cattle cause cells Cenozoic cent century changes chemical chlorophyll climate coal common compounds crops cultivated culture death rate destroy disease distribution domestic animals early earth eaten eggs elements enemies Europe evidence fact fish forms germ germ cells hawk heat horse human hydrogen Ibid important increase Indian insects iron killed known land later light live man's metals mice migration miles moth native nature neolithic nitrogen ocean organisms oxygen Pará rubber tree parasites plants and animals population pounds produce protoplasm R. S. LULL race regions rodents season seeds seems sharp-shinned hawk sheep soil South South America species square mile substances sugar supply surface survive tarpan temperature thousand tion to-day trees tropics types United wild